Adapter for a low intermodulation board-to-board RF coaxial connection assembly

A coaxial connector, intended to transmit radio frequency RF signals, of longitudinal axis X, comprising:

• an outer contact forming a body/casing, which at least one end of the outer contact is slotted defining contact petals,
• a central contact and,
• at least one electrical insulating solid structure coaxially interposed between the central contact and the outer contact, which is mechanically retained in the outer contact and in which the central contact is mechanically retained,
• at least one free end of the electrical insulating solid structure having an elasticity at a periphery of the at least one free end, at a level of the contact petals of the outer contact, which is increased compared to a remainder of the at least one electrical insulating solid structure,
• wherein the outer contact and the electrical insulating solid structure is configured such that in a connection state with a complementary connector, an outer diameter of the at least one electrical insulating solid structure is substantially equal to an inner diameter of the outer contact, and
• wherein the increased elasticity is achieved by at least one axially opening groove formed on at least part the periphery of the electrical insulating solid structure.